Gas scrubbing system

ABSTRACT

Gas scrubbing system comprising a flat surfaced tapered input quencher sealed to an entrance duct via a water seal arrangement which includes a weir arrangement to control a flow of flushing water, an elbowed connector having flat internal surfaces a spin damper having upper and lower finite clearances and a cyclonic scrubber with supplemental tangential air inlets at the spin damper level, doughnut and disc shaped baffle plates semitangentially oriented gas outlet and individually supplied water spray nozzles.

United States Patent 1151 3,696,590 Richmond 5] Oct. 10, 1972 [5 GASSCRUBBING SYSTEM 1,637,597 8/1927 Ulrici ..123/ 142.5 2,086,007 7/ 1937Tompkins ..285/183 [72] Invenmr' fi 'gfi'f f 2,267,426 12/1941 Saunderset a1. 106/287 2,197,595 4/1940 Schneible ..55/310 ig NicholsEngineering 1. a c 2,354,674 8/1944 Fisher ..55/238 x Corporation, NewYork, NY. 2,705,671 4/1955 Bencowitz ..23/278 2,869,677 1/1959 Yellottet a1 ..55/426 [22] 1969 3,057,605 10/1962 Stone ..156/196 [21] Appl.No.: 850,265 3,075,753 1/1963 Akin ..261/119 3,085,793 4/1963 Pike et a1..261/112 Dam 3,093,468 6/1963 KIOChta ..55/238 [63] Continuation ofSer; No, 636,152, May 4, 798,287 8/1905 Lawton 61 3.1 ..261/7 1967'abandmed' FOREIGN PATENTS OR APPLICATIONS [52] US. Cl. ..55/238, 55/257,55/418, 925,711 5/1963 Great Britain 261/79 A, 261/112, 261/DIG. 54939,656 10/1963 Great Britain [51] Int. Cl ..B0ld 47/10, BOlf 3/04940,930 11/ 1963 Great Britain [58] Field of Search ..261/112, 79.1,DIG. 54;

55/257, 418, 238 Primary Examiner-Frank W. Lutter Attorney-Ward,McElhannon, Brooks and Fitzpatrick [56] References Cited [57] ABSTRACTUNITED STATES PATENTS Gas scrubbing system comprising a flat surfaced3,104,965 9/1963 Mast ..55/417 tapered input quencher Sealed to anentrance duct via 3,112,352 11/1963 Krantz ..261/36 a Water Sealarrangement which includes a weir 3,131,237 4/1964 Col11ns,Jr ..261/153rangemem to control a flow of flushing water, an 3,145,239 8/1964 (11116616 ..261/112 bowed connector having flat internal surfaces 3 spin3,182,977 5/ 1965 Erm ..261/112 damper having upper and lower finiteclearances and 3,218,047 11/1965 Calaceto ..261/71 a cyclonic scrubberwith Supplemental tangential air 3,233,882 2/1966 Calaceto ..261/118inlets at the Spin damper level, doughnut and disc 3,284,064 11/1966Kolmetal ..5-5/418 x shaped baffle plates semi tangemially oriented gas3,304,695 2/1967 Krochta ..261/79.1 X outlet and individually li d waterspray l 3,315,444 4/1967 De Seversky ..55/122 3,315,445 4/ 1967 DeSeverskv ..261/79.1 X 8 Claims, 7 Drawing Figures SHEET 1 BF 5 INCQM/NGHor GAS'ES INVENTOR. CH/wus A. fiov/vo/vp PATENTEDucr 10 m2 SHEET 2 0F 5Fig.7. BY

INVENTOR. Can/945s A. P/c/mcwo ATm/P/YEYS PATENTEDum 10 1912 3.6 96. 59O SHEET 3 OF 5 INVENTOR. fil /news A. P/owswo GAS SCRUBBING SYSTEM Thisapplication is a continuation of my copending application, Ser. No.636,152, filed May 4, 1967, (now abandoned).

This invention relates to the treatment of gases and more particularlyit concerns the removal of particulate matter and other foreignsubstances from suspension in various gases.

The present invention is especially advantageous in connection with thecleaning of hot exhaust gases from combustion and similar chemicalprocesses. These gases, when left uncleaned, may cause harmful effectsto health and are considered a principle source of air pollution.

The present invention involves the processing of particle carrying gasesby subjecting them to high velocities and sudden changes in theirdirection of movement whereby the heavier particles are forced againstvarious surfaces from which they are washed or flushed by water sprays.

Basically, the present invention involves a novel cyclone type gasscrubbing device and a novel gas feed arrangement for the scrubbingdevice. The novel scrubbing device comprises a generally cylindricalscrubber tank having a tangentially oriented gas inlet and a gas outletaxially displaced from the inlet. Novel gas flow control means andscrubber cleaning arrangements are provided within the scrubbing device.The novel gas feed arrangement similarly includes specially configuredgas flow control means and scrubber cleaning means.

As illustratively embodied, the novel gas feed arrangement of thepresent invention includes a quencher into which hot gases to beprocessed are fed. The quencher has a square tapering cross sec tionwhich causes the gases to increase in velocity as they pass through it.The entrance to the quencher is formed with a water trough about itsperiphery. A hot gas feed conduit, which extends into the quencherentrance to supply gases to it, is provided with a flange like baffleplate about its periphery; and this baffle plate extends into the watertrough to form an expansible though gas-tight seal. The water in thetrough is caused to overflow a specially configured weir plate so thatit flows down in sheet fonnation over the fiat interior walls of thequencher, thereby producing a continuous flushing action for particulatematter which collects on the quencher surfaces. The tapered quencherleads directly into a connector member which is also of square crosssectional configuration. The connector member includes a sharp rightangled elbow which produces a rapid change in direction on the highvelocity gases flowing through it, thereby throwing the heavierparticulate matter in these gases against the wall of the elbow. Watersprays are provided to flush this material from the elbow wall.

The connector opens into the scrubber gas inlet via a spin damper. Thisspin damper comprises a length of conduit, also of square cross section,in which a damper plate is mounted in flapper fashion between closed andopened positions. The damper plate is constructed such that even in itsclosed position, finite clearances remain between the top and bottomedges of the plate and the corresponding interior walls of the conduit.This permits a continuous flushing action whereby water and a certainamount of gases always flow around the edge of the damper plate toprevent the accumulation and buildup of foreign matter.

The scrubber itself is provided with special tangentially oriented inletair nozzles which serve to feed additional air to the scrubber in amanner such that control of its cyclonic action is maintainedirrespective of the position of the spin damper. Means are also providedto sense the overflow of water in through the inlet air nozzles in theevent the scrubber begins to flood.

Special baffle plates are provided within the interior of the scrubberitself to ensure that all of the gases therein become subjected to thecyclonic action. These special bafile plates include a lower doughnutshaped lower plate having a central circular opening therein, and anupper circular disc shaped plate mounted centrally within the scrubber.These plates cooperate to divert all gases within the scrubber into itscyclonic stream.

The scrubber gas outlet includes a gas conduit which extends a shortdistance into the scrubber, thereby forming protective walls whichprevent mud, water, etc., which creep along the interior walls of thescrubber, from passing out through the gas outlet. The gas outletmoreover is oriented so that it extends primarily in a tangentialdirection with respect to the scrubber, but at the same time it isoriented slightly offtangent so that it possesses a finite radialcomponent. This arrangement serves to produce an extra spin velocity tothe gases just before they exit from the scrubber, and thereby removesany particulate matter not previously extracted.

A special water spray nozzle and manifolding system is provided inassociation with the scrubber of the present invention. This specialsystem includes several spray nozzles individually threaded into thescrubber walls and individually supplied with water via the manifoldingsystem. Whereas in prior arrangements where a plurality of nozzles wereconnected to a common manifold box supplied by a single water line, theentire group of nozzles had to be disabled to repair or clean any one ofthem. This difficulty is avoided with the novel nozzle and manifoldarrangement of the present invention.

There has thus been outlined rather broadly the more important featuresof the invention in order that the detailed description thereof thatfollows may be better understood, and in order that the presentcontribution to the art may be better appreciated. There are, of course,additional features of the invention that will be described hereinafterand which will form the subject of the claims appended hereto. Thoseskilled in the art will appreciate that the conception upon which thisdisclosure is based may readily be utilized as a basis for the designingof other structures for carrying out the several purposes of theinvention. It is important, therefore, that the claims be regarded asincluding such equivalent constructions as do not depart from the spiritand scope of the invention.

A specific embodiment of the invention has been chosen for purposes ofillustration and description, and is shown in the accompanying drawingsforming a part of the specification, wherein:

FIG. 1 is an elevational view of a gas scrubbing system embodying thepresent invention;

FIG. 2 is a top view of the gas scrubbing system of FIG. 1;

FIG. 3 is a section view, partially cut away, taken along line 3-3 ofFIG. 2;

FIG. 4 is an enlarged perspective view, partially cut away, illustratinga portion of the gas scrubbing system of FIG. 1;

FIG. 5 is an enlarged view taken along line 5-5 of FIG. 1;

FIG. 6 is a view taken along line 66 of FIG. 5; and

FIG. 7 is a view taken along line 7-7 of FIG. 6.

The gas scrubbing system of FIG. 1 includes an elongated, generallycylindrical scrubber 10 mounted on columns 11 so that its cyclonic axisis vertical. A quencher 12 is positioned alongside the scrubber l0 andreceives incoming hot gases to be cleaned. These gases pass from thequencher 12 to the scrubber 10 via a connector 14.

As shown in FIGS. 2 and 3 the scrubber 10 comprises a cylindricaltubular housing 16 made up of several sections interconnected at flangejoints 18. The housing 16 is closed at its top end by a cover 20, and atits bottom end by a funnel shaped bottom piece 22. A waste outlet 24extends down from the center of the bottom plate 22.

As can be seen in FIGS. 1, 2 and 3, there is provided a gas inletconduit 26 which extends tangentially into the housing 16 of thescrubber 10 toward the bottom thereof. A gas outlet conduit 28 extendsout from the scrubber at an axially displaced location toward its upperend. The gas outlet conduit 28 as can be seen in FIG. 2 is generallytangential to the scrubber 10 itself. However for reasons to bediscussed more fully hereinafter, the conduit 28 is not perfectlytangential to the scrubber but instead it is actually arranged with afinite radial component of direction.

Inside the cylindrical tubular housing 16 of the scrubber 10 there isprovided a first doughnut shaped baffle plate 30 which extendshorizontally across the interior of the housing 16 at a distance F abovethe center of the gas inlet conduit. The doughnut shaped baffle plate 30has a circular opening in the center thereof this opening shown in FIG.3 to have a diameter D Displaced above the doughnut shaped baffle 30 bya distance E there is provided a centrally located disc like baffle 32.As can also be seen in FIG. 3, this disc like plate has a diameter D Aplurality of cyclone control air inlet nozzles 34 are positioned aroundthe periphery of the scrubber 10 and enter in through the tubularhousing 16 in a tangential direction at or below the level of the gasinlet conduit 26. These nozzles 34 are connected via air supply conduits36 to the atmosphere. Depending upon the pressure conditions within thescrubber 10 more or less supplemental air will be fed tangentially intothe scrubber 10 in order to control the cyclonic action which takesplace therein.

Each air supply conduit 36 is connected also via a further conduit 42 toa water level sensing device 44. Should the water level rise in thelower portion of the scrubber 10 for any reason, as for example if thewaste outlet 24 should become clogged, then water will flow back throughthe nozzles 34 and the air supply conduit 42 into the water levelsensing device 44. Means (not shown) may be provided for producing awarning signal or for automatically initiating corrective action whenthe water level in the device reaches that of the nozzles 34.

A scrubber water supply system is also provided in connection with thescrubber 10. This system includes a water supply manifold 46 which isconnected via means (not shown) to a source of scrubbing water. Aplurality of nozzle feed pipes 48 extend downwardly from the manifold 46to various levels about the outside of the scrubber 10. These nozzlefeed pipes 48 are connected to various scrubber nozzles 50 which extendin through the walls of the housing 16 into the interior of the scrubber10.

The quencher 12 includes an entrance duct 52 which is connected to apipe or other conduit through which incoming hot gases are introduced tothe system. As shown in FIG. 3, the interior of the entrance duct 52 isprovided with a lining 53 of a refractory material or some otherinsulative substance to protect it from the high temperatures of thegases passing therethrough. This insulative substance may be a castableinsulation and it may be secured to the inner walls of the entrance duct52 by means of anchor prongs 54 attached to the walls of the duct 52 andwhich are embedded at various angles into the insulative substance.

The quencher 12 itself is made from sheet metal formed into an elongatedtapered transition member 56. As can be seen in FIG. 2 the transitionmember 56 has flat walls 78 which form a square cross-section. The walls78 of the transition member 56 taper at an angle of between and from thehorizontal. It has been found that the optimum angle for these walls isabout 78 from the horizontal.

Around the top of the transition member 56 there is formed a weir trough60 in which there is maintained a bath 62 of water. A sheet metal bafflemember 64 is secured to the entrance duct 52 and extends therefrom inflange like configuration down into the bath 62 of water, therebyforming a water seal between the interior of the entrance duct 52 andthe interior of the quencher l2, and the external atmosphere. This seal,it will be noted, readily accommodates any dimensional variations whichmay occur in the entrance duct 52 or in the transition member 56. At thesame time it maintains a gas tight seal between these two members, andthe external atmosphere.

As can be seen in FIG. 4 the inner wall of the weir trough 60 hassecured thereto a control plate 66 formed along its top edge with aplurality of V-shaped notches 67. The control plate 66 is adjustablevertically with respect to the level of the water bath contained withinthe trough 62 so as to control the rate at which water overflows throughthe V-shaped notches 67. In this manner a controlled and even flow ofwater is caused to flow down over the inner surfaces of the transitionmember 56 in sheet like formation. This adjustment is made possible bybolts 68 which pass through elongated slots 69 in the control plate andwhich tighten it against the weir trough 60 itself. About midway downthe transition member 56 there are provided a plurality of spray nozzles70 which receive water from a source (not shown) and spray it into theinterior of the transition member 56 to aid in agglomerating andincreasing the density or particulate matter contained in the gaseswhich pass through the transition member 58. These jets of watercooperate with the sheets of water which flow down the inner surfaces ofthe transition member to wash down the particulate matter and preventits buildup on the surfaces of the quencher 12.

The connector 14 is formed of a rectangularly crosssectionalconduit andincludes a vertical input portion 72, an intermediate elbow portion 73and an output portion 74. The vertical input portion 72 matches thebottom of the quencher transition member 56 and extends down from it tothe elbow portion 73. The elbow portion 73, constitutes a sharp rightangled bend which, as shown in FIG. 4, includes upper and lower slantedbend walls 75 and 7 6. The bend formed by the walls 75 and 76 serves toinduce centrifugal effects upon the particulate matter passingtherethrough and because of the high velocity imparted to the gases byvirtue of the decreasing cross section of the transition member 56 ofthe quencher, this centrifugal action forces the heavier particlesagainst the lower bend wall 76. A plurality of water nozzles 80 enterinto the connector 14 and spray water from a source (not shown) downover the wall 76 thereby flushing and scrubbing off the particulatematter which accumulates on the wall 76.

The horizontal output portion 74 of the connector 14 is coupled to thegas inlet conduit 26 of the scrubber 10. Within the gas inlet conduitthere is mounted a spin damper 90, the constructional features of whichare shown in FIGS. 5-7. The spin damper 90 is made up of an elongatedrectangular damper plate 91 which fits into the rectangularly shaped gasinlet conduit 26 and is mounted to pivot about a vertical axle 92located closely adjacent one of the side walls of theinlet conduit 26.As can be seen in the top view of FIG. 5 the damper plate 91 may swingthrough an angle of approximately 30 between its fully opened and fullyclosed positions. The axle 92 has attached to its upper end a swing arm94 which in turn is pivotally connected to a threaded block 96. Thethreaded block 96 rides along a threaded shaft 98 which is mounted torotate about a horizontal axis above the gas inlet conduit 26. A motor98 is provided to drive the shaft 96 through a chain and sprocketassembly 100. The motor 98 may be overriden and the shaft 96 turnedmanually by means of a hand crank 102. A pointer 104 may be provided onthe end of the swing arm 94, and an index plate 106 may be mounted underthe pointer to provide an indication of the position of the spin damper90.

It will be noted that the vertical height of the spin damper 90 is lessthan that of the gas inlet conduit 26 so that there are provided at alltimes finite clearances 110 between the upper and lower edges of thespin damper 90 and the associated upper and lower walls of the gas inlet26. As will be explained more fully hereinafter, this arrangementpermits a self cleaning flushing action by which accumulations of dirtand other foreign material to be removed from the gases passing throughthe system are prevented from following the spin damper operation.

During operation of the above described system hot gases to be cooledand cleaned are fed from a furnace or other gas generator (not shown)into the entrance duct 52; and from there they pass through the quencher12. During this time the baffle member 64 on the entrance duct 52extends down into the water bath 62 in the weir trough to maintain anexpansible though gas tight seal.

The control plate 66 around the inner edge of the weir trough 60 is madeup of several sections, one extending along each flat edge of the weirtrough. The height of each section is individually adjusted to controlthe overflow of water down into the quencher 12 so that an even andcomplete film of flowing water will be maintained over the flat internalsurfaces of the transition member 56. The notches 68 on the controlplate 60, which are preferably at an angle of about 60, permit moreefficient use of water in that they produce a thinner, though stillcomplete and uniform film of flowing water.

The square cross section of the quencher l2 and weir arrangement alsoserves to maintain an even and complete film of flowing water. Thisprevents the occurrence of dry spots along the interior of the quencherwhich would permit the buildup of solid material. The flat walls of theweir and quencher arrangement also eliminates rolling operations infabrication, thereby avoiding stress corrosion which accompanies rollingto circular shapes.

The hot gases, in passing through the tapered transition member 56arecooled by a screen of water spray from the nozzles 70. The flow ofwater from these nozzles and from the weir arrangement is adjusted tokeep all interior surfaces wet. This in combination with the speciallychosen taper angle of the transition member 56 serves to keep thequencher 12 flushed clean at all times.

During their passage through the quencher 12 the gases to be cleaned areincreased in velocity as they pass from the large cross sectional inletand to the smaller cross sectional outlet end, and into the similarlysmall cross sectional connector 14. The gases are thus maintained athigh velocity in the connector 14 and as they traverse the elbow portion73, the heavier particulate matter becomes greatly affected bycentrifugal force effects according to the relation v' /Zg, where v isthe gas velocity and g is the gravitational constant. Thus the heavierparticles are thrown against the lower flat slanted bend wall 76. Theseparticles are intermittently flushed down from this wall by streams ofwater from the nozzle 80.

The gases, after passing through the connector 14 enter into thescrubber 10 via the spin damper 90. The velocity of the gases enteringthe scrubber is controlled by the positioning of the spin damper plate91. As stated above, the spin damper plate 91 is especially designed toleave finite clearances above and below it in both its opened and closedpositions. The damper thus becomes self cleaning since a gas streamcontinually flows over its upper edge while both gas and water flowunder its lower edge to sweep away solid particles before they canaccumulate and impair its operation.

The gases upon passing into the scrubber 10 are subjected to cyclonicaction as they spin around the inside surfaces of the housing 16 andgradually move up toward the gas outlet conduit 28. In this cyclonicaction, the particulate matter is thrust against the walls of thehousing 16 and is flushed down by sprays from the nozzles 50 and isultimately disposed of via the waste outlet 24.

During operation of the system the velocity of the incoming gases variesaccording to the adjustment of the spin damper 90. As a result thecyclonic separation action is affected. In the present invention this iscompensated for by the presence of the tangentially oriented air inletnozzles 34 which supply supplemental air to maintain the velocity andvolume of the gases in the scrubber at optimum values.

An additional feature of the supplemental air inlet nozzles 34 is thatwhen they are positioned at or below the level of the gas inlet conduit28, (preferably at the level of its midpoint), they also serve aswarning indicators for flooding of the scrubber 10 itself. This is dueto the fact that flooding water will flow out of the scrubber and backthrough the nozzles where it can be detected and necessary correctiveaction taken before the gas inlet conduit 26 is covered and dangerousback pressure is built up in the gas source. As a result of thislimiting of flooding water height, it is possible to use lighter weightsteel in the scrubber.

The baffle plates 30 and 32 serve to direct the gases inside thescrubber so that they are nearly all subjected to the full cycloniceffects. Without these baffle plates there is a tendency for thescrubber to core; that is, some of the gases will pass up the center ofthe device without being subject to cyclonic action. Also, these baffleplates prevent the upward creep of water and solids along the innerwalls of the housing 16. This creep, if not prevented, will rise untilit passes out of the scrubber. In such event gas removal efficiency willbe severely impaired, particularly when gas volume is changed say from10 percent to 150 percent of design capacity.

It has been found that there are various dimensional relationships whichshould be maintained to obtain maximum benefit from the baffle platearrangement. These relationships are as follows:

where:

D inside diameter of the scrubber D inside diameter of the doughnutshaped baffle plate 30 D diameter of the disc like baffle 32 E verticaldistance between the baffle plates 30 and 32 F vertical distance betweenthe center of the gas inlet conduit 26 and the doughnut shaped baffleplate 30 C vertical dimension of the gas inlet conduit 26. Uponcompletion of their passage through the scrubber 10 the gases are thensubjected to an even greater velocity increase due to the nearlytangential component of orientation of the gas outlet conduit 28. Thispositioning of the gas outlet conduit causes the gases to rotate at avelocity of 60 to 70 feet per second and thereby effectively demiststhem. As mentioned above, the positioning of the gas outlet conduit sothat it projects slightly into the interior of the scrubber, togetherwith the slight radial orientation of the outlet conduit, serves tocreate a flange like protective wall which prevents the sold and liquidmaterial along the inner walls of the scrubber from entering the gasoutlet conduit.

Having thus described my invention with particular reference to thepreferred form thereof, it will be obvious to those skilled in the artto which the invention pertains, after understanding my invention, thatvarious changes and modifications may be made therein without departingfrom the spirit and scope of my invention, as defined by the claimsappended thereto.

What is claimed as new and desired to be secured by Letters Patent is:

1. A gas cleaning apparatus comprising a gas scrubber having a gas inletand a gas outlet, a gas inlet supply means for conveying gases to saidgas inlet, said gas inlet supply means including a gas scrubber inletconduit configured to define a gas flow path which extends downwardly toa bend and horizontally from said bend, and which is formed entirely ofcompletely flat internal surfaces and means for evenly distributing acontinuous flow of liquid down over said surfaces, said last-mentionedmeans comprising trough means about the periphery of said conduit at itsupper end, a plurality of flat weir plates, securing means arranged tosecure said weir plates to each of different surfaces of said conduit toextend beyond said surfaces at said one end of said conduit to forminside walls of said trough means, means for adjusting the position ofsaid weir plates with respect to said surfaces and said gas inlet supplymeans further including an entrance duct, a flange-like baffle memberextending downwardly from said entrance direct into said trough means.

2. A gas cleaning apparatus as in claim 1, wherein said means for evenlydistributing a continuous flow of liquid includes supplementary waterspray nozzles arranged to direct a spray of water along the lowerinternal surfaces of said bend.

3. A gas cleaning apparatus as in claim 1, wherein one end of said gasinlet conduit extends in a vertical direction and surrounds an entranceduct, said gas inlet conduit between said one end and said change indirection being tapered inwardly in a downward direction and beingprovided with water spray nozzles along its taper.

4. A gas cleaning apparatus according to claim 1, wherein said flatinternal surfaces include a slanted bend wall extending between andarranged at an angle with respect to each of two walls defining thedirections of said path on opposite sides of said bend.

5. A gas cleaning apparatus as in claim 1, wherein said gas inlet supplymeans includes a tapered transition member having a large inletcross-section for receiving gases to be cleaned and a small outletcrosssection coupled to said gas conduit.

6. A gas cleaning apparatus as in claim 5, wherein said gas inlet supplymeans includes means defining a water trough about the inlet of saidtapered transition member and means for controlling overflow of waterfrom said trough down over the interior surfaces of said taperedtransition member.

7. A gas cleaning apparatus as in claim 1, wherein said gas inlet supplymeans includes an entrance seal comprising means defining an inletopening and means forming a water trough about said inlet opening, anentrance duct extending into said inlet opening and a flange baffleplate member secured to said entrance duct and into said water trough.

8. A gas scrubbing system comprising a cylindrically shaped cyclone-typegas scrubber, a gas inlet conduit extending tangentially into the sideof said gas scrubber, a gas outlet conduit, extending from said gasscrubber at a location axially displaced from said gas inlet conduit,baffle means located within said gas scrubber and including a firstdisc-shaped member and a second annular-shaped member, said disc-shapedmember being positioned closer to said gas outlet conduit than saidannular-shaped member, a gas inlet supply means for conveying gases tosaid gas inlet conduit, said supply means comprising an upper verticalgas inlet portion, a lower horizontal portion and an intermediate elbowportion providing a sharp angled bend between said vertical andhorizontal portions, said vertical gas inlet portion being tapered andprovided with flat internal surfaces, means for causing a continuousfilm of liquid to flow down over said internal surfaces, liquid spraymeans arranged to direct liquid sprays into said tapered verticalportion, and adjustable spin-damper means arr ged inside said horizontalportion to control gas w into said scrubber, said spin-damper meanshaving means for providing clearance between said spin-damper means andthe inner surfaces of said horizontal portions in all positions of saidspin-damper means, thereby to permit liquid to flow by said spin-dampermeans at all positions thereof.

1. A gas cleaning apparatus comprising a gas scrubber having a gas inletand a gas outlet, a gas inlet supply means for conveying gases to saidgas inlet, said gas inlet supply means including a gas scrubber inletconduit configured to define a gas flow path which extends downwardly toa bend and horizontally from said bend, and which is formed entirely ofcompletely flat internal surfaces and means for evenly distributing acontinuous flow of liquid down over said surfaces, said last-mentionedmeans comprising trough means about the periphery of said conduit at itsupper end, a plurality of flat weir plates, securing means arranged tosecure said weir plates to each of different surfaces of said conduit toextend beyond said surfaces at said one end of said conduit to forminside walls of said trough means, means for adjusting the position ofsaid weir plates with respect to said surfaces and said gas inlet supplymeans further including an entrance duct, a flange-like baffle memberextending downwardly from said entrance direct into said trough means.2. A gas cleaning apparatus as in claim 1, wherein said means for evenlydistributing a continuous flow of liquid includes supplementary waterspray nozzles arranged to direct a spray of water along the lowerinternal surfaces of said bend.
 3. A gas cleaning apparatus as in claim1, wherein one end of said gas inlet conduit extends in a verticaldirection and surrounds an entrance duct, said gas inlet conduit betweensaid one end and said change in direction being tapered inwardly in adownward direction and being provided with water spray nozzles along itstaper.
 4. A gas cleaning apparatus according to claim 1, wherein saidflat internal surfaces include a slanted bend wall extending between andarranged at an angle with respect to each of two walls defining thedirections of said path on opposite sides of said bend.
 5. A gascleaning apparatus as in claim 1, wherein said gas inlet supply meansincludes a tapered transition member having a large inlet cross-sectionfor receiving gases to be cleaned and a small outlet cross-sectioncoupled to said gas conduit.
 6. A gas cleaning apparatus as in claim 5,wherein said gas inlet supply means includes means defining a watertrough about the inlet of said tapered transiTion member and means forcontrolling overflow of water from said trough down over the interiorsurfaces of said tapered transition member.
 7. A gas cleaning apparatusas in claim 1, wherein said gas inlet supply means includes an entranceseal comprising means defining an inlet opening and means forming awater trough about said inlet opening, an entrance duct extending intosaid inlet opening and a flange baffle plate member secured to saidentrance duct and into said water trough.
 8. A gas scrubbing systemcomprising a cylindrically shaped cyclone-type gas scrubber, a gas inletconduit extending tangentially into the side of said gas scrubber, a gasoutlet conduit, extending from said gas scrubber at a location axiallydisplaced from said gas inlet conduit, baffle means located within saidgas scrubber and including a first disc-shaped member and a secondannular-shaped member, said disc-shaped member being positioned closerto said gas outlet conduit than said annular-shaped member, a gas inletsupply means for conveying gases to said gas inlet conduit, said supplymeans comprising an upper vertical gas inlet portion, a lower horizontalportion and an intermediate elbow portion providing a sharp angled bendbetween said vertical and horizontal portions, said vertical gas inletportion being tapered and provided with flat internal surfaces, meansfor causing a continuous film of liquid to flow down over said internalsurfaces, liquid spray means arranged to direct liquid sprays into saidtapered vertical portion, and adjustable spin-damper means arrangedinside said horizontal portion to control gas flow into said scrubber,said spin-damper means having means for providing clearance between saidspin-damper means and the inner surfaces of said horizontal portions inall positions of said spin-damper means, thereby to permit liquid toflow by said spin-damper means at all positions thereof.